1. Field of the Invention
This invention relates to a photoelectric switch, and in particular to a photoelectric switch having a display section.
2. Discussion of the Related Art
A photoelectric switch is used to detect the presence or absence of a detected object on the manufacturing premise, as for example, in a production inspection step. The demands for the manufacturing premises to make industrial products, such as miniaturization, manufacturing cost reduction, quality improvement, etc., are increasingly severe with each passing year. In such an environment, the performance required for various sensors or switches is also becoming higher and the demands for higher functionability stronger. The demand for saving space affects the photoelectric switch and additional miniaturization of the electric switch is always needed.
Some known photoelectric switches in the related arts comprise a display section. In this kind of photoelectric switch, for example, while a threshold value is displayed, a switch or a button can be pressed to finely adjust the setup threshold value.
When a large number of functions are set or adjusted, the number of times a button or a switch is operated is increased to display information concerning the setting or adjusting. If the spacing between adjacent buttons or switches becomes narrower with miniaturization, the problem of erroneous operation is always involved. Once an erroneous operation is performed, to start again from the beginning, a button or a switch is repetitively pressed to return to the initial display item and further a button or a switch must be pressed multiple times to return to the problem display item. This extremely burdensome work is forced on the user.